Modular pavement slab

ABSTRACT

A modular pavement slab comprises a body, a strain sensor array, and a sensor processor. The body includes a top surface, a bottom surface, and four side surfaces. The modular pavement slab is configured to be coupled to at least one other modular pavement slab via connectors along at least one of the side surfaces. The strain sensor array is retained within the body and is configured to detect a plurality of strains on the body resulting from vehicular traffic across the top surface of the body. The sensor processor is in communication with the strain sensor array. The sensor processor is configured to communicate input signals to the strain sensor array, receive output signals from the strain sensor array, and determine a plurality of time-varying strain values, each strain value indicating a strain experienced over time by a successive one of a plurality of regions of the body.

RELATED APPLICATION

The current patent application is a continuation patent applicationwhich claims priority benefit with regard to all common subject matterto identically-titled U.S. patent application Ser. No. 16/528,024, filedJul. 31, 2019, which, itself, claims priority benefit with regard to allcommon subject matter to U.S. patent application Ser. No. 15/889,718,filed Feb. 6, 2018 (now U.S. Pat. No. 10,407,838), which, itself, claimspriority benefit with regard to all common subject matter to thefollowing identically-titled U.S. Provisional Applications: ApplicationNo. 62/455,287, filed Feb. 6, 2017; and Application No. 62/594,822,filed Dec. 5, 2017. Each of the earlier-filed provisional andnon-provisional applications is hereby incorporated by reference in itsentirety into the current application.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates generally to the field of pavement systems and,in particular, to a pre-fabricated, modular pavement slab equipped forembedded self-monitoring of form and integrity.

Description of the Related Art

Pre-fabricated, modular pavement slabs have traditionally offered anattractive alternative to continuous pour systems at least because theycan be individually removed, repaired and/or replaced with relativeease. Traditional continuous pour systems require significantly moretime and/or money for removal and replacement.

However, pre-fabricated, modular pavement slab systems have untappedpotential for enabling focused, quick and low-cost maintenance and/orrepair. For instance, defect detection for the slab and/or sub-grade isstill overwhelmingly performed using the same traditional tools used incontinuous pour systems. A serviceable modular pavement slab is neededto improve the longevity and usefulness of such alternatives tocontinuous pour systems.

SUMMARY OF THE INVENTION

Embodiments of the current invention solve the above-mentioned problemsand provide a distinct advance in the arts of modular pavement slabsthat provide pavement condition indexing and vehicle position sensing.

An embodiment of the modular pavement slab comprises a body, a strainsensor array, and a sensor processor. The body includes a top surface.The strain sensor array is retained within the body and is configured todetect a plurality of strains on the body resulting from vehiculartraffic across the top surface of the body. The sensor processor is incommunication with the strain sensor array. The sensor processor isconfigured to communicate input signals to the strain sensor array,receive output signals from the strain sensor array, and determine aplurality of time-varying strain values, each strain value indicating astrain experienced over time by a successive one of a plurality ofregions of the body.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Other aspectsand advantages of the current invention will be apparent from thefollowing detailed description of the embodiments and the accompanyingdrawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Embodiments of the current invention are described in detail below withreference to the attached drawing figures, wherein:

FIG. 1 is a top schematic view of a self-monitoring modular pavementslab according to the present inventive concept;

FIG. 2 is an elevated schematic view of the self-monitoring modularpavement slab of FIG. 1 illustrating a sensing body; and

FIG. 3 is a schematic block diagram of various electronic components ofthe self-monitoring modular pavement slab of FIG. 1.

The drawing figures do not limit the current invention to the specificembodiments disclosed and described herein. While the drawings do notnecessarily provide exact dimensions or tolerances for the illustratedcomponents or structures, the drawings are to scale as examples ofcertain embodiments with respect to the relationships between thecomponents of the structures illustrated in the drawings.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The following detailed description of the invention references theaccompanying drawings that illustrate specific embodiments in which theinvention can be practiced. The embodiments are intended to describeaspects of the invention in sufficient detail to enable those skilled inthe art to practice the invention. Other embodiments can be utilized andchanges can be made without departing from the scope of the presentinvention. The following detailed description is, therefore, not to betaken in a limiting sense. The scope of the present invention is definedonly by the appended claims, along with the full scope of equivalents towhich such claims are entitled.

In this description, references to “one embodiment”, “an embodiment”, or“embodiments” mean that the feature or features being referred to areincluded in at least one embodiment of the technology. Separatereferences to “one embodiment”, “an embodiment”, or “embodiments” inthis description do not necessarily refer to the same embodiment and arealso not mutually exclusive unless so stated and/or except as will bereadily apparent to those skilled in the art from the description. Forexample, a feature, structure, act, etc. described in one embodiment mayalso be included in other embodiments, but is not necessarily included.Thus, the current technology can include a variety of combinationsand/or integrations of the embodiments described herein.

Prior art pre-cast slabs have long been recognized as an alternative tocontinuous pour solutions, which have been more popular traditionallywithin the United States. Part of the appeal offered by pre-cast pavingsystems is serviceability—when a portion of pavement requires service,it may be removed and replaced with relative ease as compared withsimilar repair efforts using continuous pour solutions aimed atrestoring the pavement to like-new condition. Nonetheless, defectswithin the body of a pavement slab and/or in the underlying sub-grademay exist for years prior to detection, which may lead to additionaldamage and more expensive repair efforts.

Embodiments of the present inventive concept improve existing detectionmethods and apparatus by providing a permanent, embedded form-monitoringsystem comprising a plurality of strain gauges distributed in an arrayacross at least a portion of the length and width of each pre-cast slab.The array may be substantially continuous in nature—for example, wherethe array includes one or more fiber optic cables extending in a patternthroughout the slab—and may collect data at a plurality of straindetection points regarding the transfer of force through a sensingvolume. The data collected from the strain detection points may beanalyzed locally within each slab, using an adjacent system proximate tothe slab, and/or transmitted to a remote database for analysis againstdata from neighboring slabs to detect developing defects in the sensingvolume and/or underlying sub-grade. The data may also or alternativelybe put to additional uses, including vehicle monitoring providingpositional data, vehicle weights, speeds, axle widths, axle lengths,traffic patterns, vehicle behaviors, and other information that can bedetected through monitoring the internal and external deformations ofthe pavement slab.

Collection of data regarding changes over time in how a segment and itssurrounding segments within the sensing volume transfer forcestherethrough may permit modeling of sufficient resolution to detectdefects in the paving apparatus and/or in the underlying sub-grade.Moreover, accelerations, gyroscopic motion, magnetic fields,temperature, salinity, water content and additional properties may bedetected within each slab to enhance data resolution and permit easieridentification of changes in slab form and/or integrity and/or tomonitor atmospheric or environmental conditions.

Turning to FIGS. 1-2, a pre-cast, self-monitoring modular pavement slab10 according to an embodiment of the present inventive concept broadlycomprises a body 12 generally having a rectangular box shape with anupper surface 14, a bottom surface 16, and four side surfaces 18, 20,22, 24. The body 12 may be composed primarily of precast concretepavement. The body 12 may also or alternatively comprise asphalt,plastic material, fiberglass, carbon fiber, geopolymers and/or othermaterials that may serve as and/or support driving surfaces withoutdeparting from the spirit of the present inventive concept.

The modular pavement slab 10 may include a plurality of access ports 26defined in and below the upper surface 14 (it should be noted that thethird and fourth access ports are not illustrated in FIG. 2 to avoidobscuring other components). The access ports 26 may house embeddedlifting receivers (not shown) and are spaced for balanced lifting of thebody 12. Access ports may also permit fluid communication between upperand bottom surfaces and may be configured to house and/or provide accessto other sensing equipment (see incorporations by reference below)without departing from the spirit of the present invention.

Two opposing side surfaces 18, 22 define dowel cavities 28 therein thatextend within and toward the center of the body 12. Dowel rods 30 mayextend at least partway out of the cavities 28—for example where themodular pavement slab 10 is assembled to neighboring structures such asother paving apparatus—and each may be secured in place within the slaband/or a neighboring structure, following assembly, using grouting orthe like.

It is foreseen that additional of the substantially vertical sidesurfaces or faces of a body may include dowel cavities and rods withoutdeparting from the spirit of the present inventive concept. It is alsoforeseen that other load-transferring structure may be used in lieu ofor in addition to dowel rods without departing from the spirit of thepresent inventive concept. A rubber skirt, backer board, spacing rod,tar mixture, grouting or similar buffering substance may also be placedin seams between a modular pavement slab and neighboring structuresand/or below the modular pavement slab. A modular pavement slabpreferably also includes an internal reinforcement grid (not shown),which may be comprised of at least two layers of steel rebar lattice orother known internal reinforcement structures such as fiberglassreinforcement mat, geotechnical mat, carbon fiber mat, or loosereinforcement material such as fiberglass fibers, carbon fibers, plasticfibers, or metallic shavings. More broadly, it is foreseen thatembodiments of the present inventive concept are interoperable with thepaving systems and apparatuses described in U.S. Patent Publication No.2016-0222594 A1 to Sylvester and in U.S. Patent Publication No.2017-0191227 A1 to Sylvester, each of which is hereby incorporated byreference herein in its entirety.

The modular pavement slab 10 also includes a strain sensor array 32distributed at least partly across the length and width of body 12.Strain sensor array 32 includes a plurality of optical fiber sensors. Inthe exemplary embodiments shown in the figures, the strain sensor array32 includes first and second optical fiber sensors 34, 36. Each opticalfiber sensor 34, 36 may include optical fiber sensing technologiesincluding but not limited to one or more methods such as Rayleigh,Brillouin, Raman, or Fiber Bragg Grating (FBG) technologies, distributedalong the length thereof. In the described method using FBGs, the FBGsare positioned in the optical fiber with selectable space therebetween.Each FBG, or any other method implemented as described above but notlimited to those specifically named, provides a measurement of thestrain of its surrounding environment, which is a local volume or regionof the body 12. Alternatively, or additionally, each optical fibersensor 34, 36 may include a plurality of individually packaged FBGscoupled to one another with a plurality of optical fibers, with eachoptical fiber coupling two FBGs. Generally, each FBG reflects an opticalsignal, of a particular wavelength or small band of wavelengths, that itreceives. The characteristics, such as intensity, amplitude, wavelength,and/or time delay, of the optical signal reflection may vary accordingto a strain, potentially among other factors, placed on the FBG.

The optical fiber sensors 34, 36 are shown in the figures to beimplemented with a circular or oval layout within the body 12. However,the optical fiber sensors 34, 36 may be implemented within the body 12in a serpentine pattern layout, a coil pattern layout, a grid pattern,an array of individual fiber optic lines, or other geometric patternlayouts. In addition, the first optical fiber sensor 34 may have a firstlayout, while the second optical fiber sensor 36 may have a secondlayout. The optical fiber sensors 34, 36 are also shown to occupyseparate regions of the body 12. In other embodiments, the optical fibersensors 34, 36 may overlap one another, for example along the depth orheight of the body 12, or may otherwise occupy the same region of thebody 12 within a given plane. While the drawings demonstrate two fibers,a plurality of fibers may be incorporated into the functional unitincorporating one or more fiber patterns, or fiber optic sensingmethods, within the body of a slab.

The positioning of the FBGs or alternative sensing elements of othersensing methods within each optical fiber may be selected in combinationwith the layout of each optical fiber sensor 34, 36 to establish adesired resolution of the strain measurements throughout the volume ofthe body 12 (e.g., within the boundaries of the body 12 illustrated inFIG. 2) and/or with respect to the surface area of the upper surface 14of the body 12. For example, a smaller spacing between FBGs within theoptical fiber sensors 34, 36 produces a greater resolution of strainmeasurements, while a larger spacing leads to lower resolution. Inaddition, layout patterns of the optical fiber sensors 34, 36 such as aserpentine or coil produces a greater resolution of strain measurements,while patterns such as a circle provide lower resolution.

In an embodiment, a strain sensor array may include at least threeoptical fiber sensors (not shown) arranged in a linear layout andpositioned within a slab along the length thereof. In such embodiments,each optical fiber sensor may extend along a majority of the length ofthe slab and be positioned in proximity to, and association with, awheel path of vehicles travelling on a corresponding apparatus. Forexample, a first and a second optical fiber sensor may be placed closerto outer edges of the slab along the wheel paths of most automobiles andtrucks. A third optical fiber sensor may be placed close to the centerof the slab along the wheel path of a motorcycle. It is foreseen,however, that in certain embodiments strain sensor arrays may include aplurality of strain sensors distributed across a portion of the lengthand width of the paving apparatus without departing from the spirit ofthe present inventive concept. One of ordinary skill will alsoappreciate that arrays including solid-state strain gauges, vibratingwire strain gauges, load cells, piezo-electric elements and/or similarknown sensors are within the scope of the present invention.

While it is foreseen that embodiments of the present inventive conceptmay be constructed in the field or on site—for example as part of acast-in-place installation—or be pre-fabricated into an assembly thatcan be installed into alternative paving materials such as asphalt orcast-in-place concrete, it is preferred that the strain sensor array 32be encased and permanently fixed within body 12 during an offsitepre-fabrication process. The optical fiber sensors 34, 36 may belaminated and/or fixed to a top side of a bottommost reinforcement layer(not shown, but see, e.g., FIGS. 2-4 of U.S. Patent Publication No.20170191227A1) of the modular pavement slab 10 during fabrication,essentially extending in a substantially horizontal plane at a givenheight within the body 12. Placement near the bottom of the body 12 mayprovide greater resolution from and/or amplification of data collectedby the strain sensor array 32. Moreover, fixing the strain sensor array32 to a reinforcement layer may generate a more holistic data setrepresenting changes in form across the entire body 12 because apreferred reinforcement layer will extend across substantially theentire length and width of the body 12 and may be less susceptible tolocalized distortions resulting from pockets or imperfections in thebody 12.

It is foreseen that all or portions of a strain sensor array may beencased at different and/or varying heights within a slab withoutdeparting from the spirit of the present inventive concept. Forinstance, disposing at least one sensor at a different height within theslab—such as vertically above or below a second sensor—may provideadditional resolution for detecting defects in the slab. However, longdimensions of optical fiber sensors are preferably in substantialalignment with a direction of travel, for example along a length axis,which may improve detection of vehicular load progression across a topsurface of the slab.

The modular pavement slab 10 also may include at least one sensorprocessor 38 and at least one communication element 40 to provide signalcontrol and processing as well as communication, as shown in FIG. 3. Thesensor processor 38 includes a memory element 42, a processing element44, and an optoelectronic interface 46. Each sensor processor 38 may beretained within a housing that is accessible through a successive one ofthe access ports 26. In addition, each sensor processor 38 may beremovable and replaceable, and access for such removal may be protectedby a keyed security device—such as an interlock connecting the housingto the body 12 and requiring a special tool to disconnect—and/orgrouting or the like.

The memory element 42 may be embodied by devices or components thatstore data in general, and digital or binary data in particular, and mayinclude exemplary electronic hardware data storage devices or componentssuch as read-only memory (ROM), programmable ROM, erasable programmableROM, random-access memory (RAM) such as static RAM (SRAM) or dynamic RAM(DRAM), cache memory, hard disks, floppy disks, optical disks, flashmemory, thumb drives, universal serial bus (USB) drives, or the like, orcombinations thereof. In some embodiments, the memory element 42 may beembedded in, or packaged in the same package as, the processing element44. The memory element 42 may include, or may constitute, a“computer-readable medium”. The memory element 42 may store theinstructions, code, code statements, code segments, software, firmware,programs, applications, apps, services, daemons, or the like that areexecuted by the processing element 44. The memory element 42 may alsostore settings, data, databases, and the like.

The processing element 44 may include electronic hardware componentssuch as processors, microprocessors (single-core or multi-core),microcontrollers, digital signal processors (DSPs), field-programmablegate arrays (FPGAs), analog and/or digital application-specificintegrated circuits (ASICs), or the like, or combinations thereof. Theprocessing element 44 may generally execute, process, or runinstructions, code, code segments, code statements, software, firmware,programs, applications, apps, processes, services, daemons, or the like.The processing element 44 may also include hardware components such asfinite-state machines, sequential and combinational logic, and otherelectronic circuits that can perform the functions necessary for theoperation of the current invention. The processing element 44 may be incommunication with the other electronic components through serial orparallel links that include universal busses, address busses, databusses, control lines, and the like.

The optoelectronic interface 46 generally converts electronic signals tooptical signals and vice versa. The optoelectronic interface 46 mayinclude photonic generator(s), such as light-emitting diodes (LEDs),lasers including top emitters, edge emitters, or the like, as well asphotodetectors, such as photodiodes, phototransistors, photoresistors,phototubes, or the like. The optoelectronic interface 46 may furtherinclude electronic circuitry such as amplifiers, filters,analog-to-digital converters (ADCs), digital-to-analog converters(DACs), and so forth. The optoelectronic interface 46 receiveselectronic signals and converts them to transmitted optical signals,i.e., electromagnetic radiation having a plurality of wavelengths in thevisible and/or infrared regions of the electromagnetic spectrum. Theoptical signals correspond to the electronic signals in amplitude,frequency, and duration. The optoelectronic interface 46 receivesoptical signals and converts them to generated electronic signals havinga voltage level, current level, power level, or the like correspondingto the optical signals in amplitude, frequency, and duration. Theoptoelectronic interface 46 may also generate an electronic data streamthat corresponds to the received optical signals.

Through hardware, firmware, software, or various combinations thereof,the sensor processor 38 may be configured or programmed to perform atleast the following functions. The sensor processor 38 generallycontrols the operation of the strain sensor array 32 by generating theinput signals and communicating them to the strain sensor array 32 andreceiving and processing the output signals of the strain sensor array32. In some embodiments, a single sensor processor 38 may be coupled toand control the operation of both optical fiber sensors 34, 36. In otherembodiments, the modular pavement slab 10 may include multiple sensorprocessors 38, each coupled to and controlling the operation of arespective one of the optical fiber sensors 34, 36. The sensor processor38 further includes an interrogator 48 as a function of the processingelement 44 or as a separate component. In some embodiments, theinterrogator 48 may further include, or be in electronic communicationwith, the optoelectronic interface 46. Utilizing the interrogator 48,the sensor processor 38 generates a plurality of optical signals, eachhaving a unique wavelength, which are transmitted through the opticalfiber sensors 34, 36. The optical signals may be transmittedsimultaneously or sequentially. The parameters of the optical signalstransmitted by the sensor processor 38 may be selectively programmable.

In the illustrated embodiment, all of the optical signals are receivedby each FBG in the optical fiber sensors 34, 36. But, each FBG mayreflect only the optical signal whose wavelength is the same as the onethe FBG is designed to reflect. Furthermore, the characteristics of thereflected optical signal, such as intensity change, amplitude change,time delay, and/or shifted wavelength, may vary according to the strainexperienced by the FBG, thus providing a measurement of the strain onthe body 12 in the local volume surrounding the FBG. The sensorprocessor 38 receives all of the reflected optical signals and analyzesthem to determine the strain at each location of an FBG. In addition,the sensor processor 38 repeats this process dozens or hundreds of timesper second.

The sensor processor(s) 38 may create a virtual database or table ofmeasured strain values that is stored in the memory element 42. Thevirtual database may include a plurality of historically-recorded strainvalues for each FBG. Since the X and Y coordinate locations (withrespect to the upper surface 14 of the body 12) of each FBG are known,the sensor processor 38 may create a time-varying virtual map of strainvalues experienced by the body 12 resulting from the weight or mass ofvehicles travelling across the upper surface 14 thereof—each strainvalue indicating a strain experienced over time by a successive one of aplurality of regions of the body 12. In addition, utilizing the changein strain along a particular path or in certain areas, such as vehiclewheel paths, the sensor processor 38 can determine a velocity vector,i.e., a speed and direction, of the vehicles traversing the uppersurface 14. Furthermore, the sensor processor 38 may utilize a lookuptable or machine learning or artificial intelligence techniques todetermine a type of vehicle that is traversing the upper surface 14based on dynamic characteristics, such as a magnitude of change inamplitude, of the measured strain values.

The communication element 40 generally allows communication withexternal systems or devices. The communication element 40 may includesignal and/or data transmitting and receiving circuits, such asantennas, amplifiers, filters, mixers, oscillators, digital signalprocessors (DSPs), and the like. The communication element 40 mayestablish communication wirelessly by utilizing radio frequency (RF)signals and/or data that comply with communication standards such ascellular 2G, 3G, 4G, LTE, or 5G, Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 standard such as WiFi, IEEE 802.16 standard suchas WiMAX, Bluetooth™, or combinations thereof. In addition, thecommunication element 40 may utilize communication standards such asANT, ANT+, Bluetooth™ low energy (BLE), the industrial, scientific, andmedical (ISM) band at 2.4 gigahertz (GHz), commercially available orcustomized Radio Frequency Identification (RFID), or the like.Alternatively, or in addition, the communication element 40 mayestablish communication through connectors or couplers that receivemetal conductor wires or metal conductor cables which are compatiblewith networking technologies such as ethernet. In certain embodiments,the communication element 40 may also couple with optical fiber cables.

In some embodiments, the modular pavement slab 10 may include a singlecommunication element 40 that is in electronic communication with theone or more sensor processors 38. In other embodiments, the modularpavement slab 10 may include a plurality of communication elements 40,each communication element 40 in electronic communication with arespective one of the sensor processors 38. In any case, thecommunication element 40 may receive measured strain values, velocitydata, and vehicle data from one or more of the sensor processors 38 andcommunicate the data to other sensor processors 38 in the same modularpavement slab 10 or other slabs 10 or external devices or systems, suchas through Bluetooth™, WiFi, and/or cellular protocols. Thecommunication element 40 may also receive programming data orinstructions for the sensor processors 38 to operate the strain sensorarray 32 from external devices or systems or other apparatuses 10. Theprogramming and instructions may be communicated to the appropriatesensor processors 38.

In various embodiments, the modular pavement slab 10 further includes aplurality of communication ports 50. Each communication port 50 mayinclude a plurality of electrical and/or optical connectors. Each of theconnectors, whether electrical or optical, may couple directly with acorresponding connector on the communication port 50 of another modularpavement slab 10 or with electrical cables or optical fibers that coupleto other communication ports 50. Each communication port 50 ispositioned on a successive one of the four side surfaces 18, 20, 22, 24of the body 12, typically close to the center of the side surface, suchthat, when the apparatuses 10 are placed next to one another to form aroad, the communication port 50 of one modular pavement slab 10 alignswith, and may couple to, the communication port 50 of its adjacentmodular pavement slab 10. In addition, each communication port 50 is inelectronic communication with one or more communication elements 40 toenable communication of measured strain values, velocity data, andvehicle data from one or more of the sensor processors 38.

The modular pavement slab 10 also includes data and/or power lines 52,54 extending between sensor processors 38 and communication elements 40.It is foreseen that the illustrated pattern of wired connection betweenelectronics of the modular pavement slab 10 may vary, and/or thatwireless communication routers may be used, without departing from thespirit of the present inventive concept. It is also foreseen that lines,cables and/or wires described herein for data and/or power transfer maycomprise a variety of materials—including cable, fiber and wires ofvarious materials—without departing from the spirit of the presentinventive concept.

In operation, as a load is applied to upper surface 14, the appliedforce may propagate through segments of the sensing volume, creatingtemporary (and, possibly, permanent) deformations in the material ofbody 12. As the propagating force deforms areas surrounding the strainsensor array 32, strains are sensed by the optical fiber sensors 34, 36and determined by one or more sensor processors 38. The time-varyingmeasured strain data may be recorded and stored in one or more memoryelements 42 and utilized to determine the presence and/or location ofvehicles on the upper surface 14, as well as their orientations,directions, speeds, weights, tire pressures, and other data points whichmay be derived from such strain distributions.

Loads on the sensing volume of the body 12 may be continuously sensedover long periods of time, with significant localized variances in howforces move through segments of the sensing volume being noted aspotentially indicative of defects in and/or damage to body 12 and/or theunderlying sub-grade. Such data may be transmitted remotely for furtherprocessing against data gathered from surrounding slabs, which mayprovide further clarity regarding the potential cause(s) ofirregularity, for example by providing relative control groups of hownearby slabs are reacting to loads. Sensor data may also oralternatively be analyzed locally and/or remotely in real time for useby navigation (e.g., autonomous) guidance systems, emergency alert andcar deviation systems, and for other uses. Data obtained from the strainsensor array 32 may also be used to measure internal and applied loads,deflection, 3D shape, moisture content and/or temperature. The data maybe analyzed to indicate vehicle location, orientation, speed, weight,and the like.

For instance, the communication elements 40 may establish direct and/orindirect communication(s) with vehicles for transmitting raw and/orprocessed data collected via the strain sensor array 32. Such data maybe used in connection with autonomous and/or self-driving technologies(e.g., Level 4 autonomous driving). In an embodiment, one or more of thecommunication elements 40 may continuously or periodically transmit suchdata—i.e., regarding objects and/or vehicles present on the slab 10(e.g., position, velocity, weight, etc.)—to one or more autonomousvehicles to support automated navigation. In a more particularembodiment, data obtained via the strain sensor arrays 32 of a system ofslabs 10 may comprise and/or be integrated into vehicular location,positioning, navigation, telemetry, or obstacle avoidance systems toprovide and/or improve accuracy of positional data in support ofautonomous driving operations.

In addition, the communication elements 40 may receive data and/orinformation from vehicles implementing autonomous and/or self-drivingtechnologies that are in the vicinity of, or traveling upon, theassociated slab 10. The data and/or information may include velocityand/or heading information, vehicle identification information, and thelike. The data and/or information may be utilized by the slab 10 forverification purposes, fault detection or correction purposes, and thelike. Additionally, or alternatively, the data and/or information may betransferred to other slabs 10 in the vicinity or in the direction oftravel of the vehicle.

It should also be noted that a benefit of the illustrated embodiment,while not required to practice the present inventive concept, ismultiple redundancies. For instance, first and second optical fibersensors 34, 36 may permit operation, albeit with potentially reduceddata resolution, even in the event one fails. Moreover, the multiplesensor processors 38 may redundantly include interrogators 48 and/orelectrical communication with the optical fiber sensors 34, 36 such thatfailure of a single sensor processor 38 does not necessarily lead toloss of any output from the strain sensor array 32. In the same vein,multiple communication elements 40 may also provide several data outputs(and, preferably, inputs) that may increase the longevity of eachmodular pavement slab 10 by providing alternative access points in theevent of a single communication element 40 failure.

Having now described the features, discoveries and principles of thegeneral inventive concept, the manner in which the general inventiveconcept is constructed and used, the characteristics of theconstruction, and advantageous, new and useful results obtained; the newand useful structures, devices, tools, elements, arrangements, parts andcombinations, are set forth in the appended claims.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the general inventiveconcept herein described, and all statements of the scope of the generalinventive concept which, as a matter of language, might be said to falltherebetween.

Although the invention has been described with reference to theembodiments illustrated in the attached drawing figures, it is notedthat equivalents may be employed and substitutions made herein withoutdeparting from the scope of the invention as recited in the claims.

Having thus described various embodiments of the invention, what isclaimed as new and desired to be protected by Letters Patent includesthe following:

1. A system comprising: a modular pavement slab having a body includinga top surface, a bottom surface, and a plurality of side surfaces, themodular pavement slab being configured to be coupled to a second modularpavement slab via load-transferring connectors along at least one of theplurality of side surfaces; a strain sensor array contacting the body,the strain sensor array configured to detect a plurality of strains onthe body resulting from traffic across the top surface of the body; asensor processor configured to— receive output signals from the strainsensor array, determine a plurality of strain values based at least inpart on the output signals from the strain sensor array, each strainvalue indicating a strain of the plurality of strains experienced by aregion of the body; and a plurality of cavities defined by the body;said load-transferring connectors extending from a first side surface ofthe plurality of side surfaces, said plurality of cavities extendinginto the body from a second side surface of the plurality of sidesurfaces.
 2. The system of claim 1, wherein the strain sensor arrayincludes first and second optical fiber sensors, each optical fibersensor including an optical fiber with a plurality of fiber Bragggratings spaced apart axially along the optical fiber.
 3. The system ofclaim 2, wherein each optical fiber sensor forms a loop and the firstoptical fiber sensor is positioned adjacent to the second optical fibersensor within the body.
 4. The system of claim 1, wherein the sensorprocessor is further configured to determine a speed and a direction ofeach vehicle that travels across the top surface of the modular pavementslab.
 5. The system of claim 1, wherein the sensor processor is furtherconfigured to determine a weight of each vehicle that travels across thetop surface of the body.
 6. The system of claim 1, wherein the sensorprocessor is further configured to determine a tire pressure of eachtire of each vehicle that travels across the top surface of the body. 7.The system of claim 1, wherein the sensor processor is furtherconfigured to determine a type of each vehicle that travels across thetop surface of the body.
 8. The system of claim 1, further comprising acommunication element in electronic communication with the sensorprocessor and configured to communicate information derived from thestrain values to other modular pavement slabs or external systems. 9.The system of claim 1, wherein the sensor processor is housed orembedded in the body of the modular pavement slab.
 10. The system ofclaim 1, wherein the modular pavement slab includes a reinforcementlayer and the strain sensor array is attached to the reinforcementlayer.
 11. The system of claim 1, wherein the strain sensor array isembedded in the body of the modular pavement slab.
 12. The system ofclaim 11, wherein the strain sensor array comprises a first opticalfiber sensor embedded in a bottom half of the modular pavement slab. 13.The system of claim 1, wherein the strain sensor array comprises a firstoptical fiber sensor having a long dimension extending in a direction oftravel.
 14. The system of claim 1, further comprising an access portdefined by the body in and below the top surface.
 15. The system ofclaim 14, wherein the sensor processor is accessible via the accessport.
 16. The system of claim 1, wherein the strain sensor arraycomprises first and second optical fiber sensors embedded at differentheights within the body relative to the top and the bottom surfaces. 17.The system of claim 1, wherein the output signals are generated inresponse to input signals communicated to the strain sensor array by thesensor processor.
 18. The system of claim 1, wherein the second sidesurface is substantially opposite from the first side surface.
 19. Thesystem of claim 1, wherein the plurality of strain values comprisetime-varying strain values.
 20. The system of claim 1, furthercomprising a connector positioned along one of the plurality of sidesurfaces configured for electronic communication with a second connectorof the second modular pavement slab.